SYNOPSIS

DESCRIPTION

The getprotoent() function reads the next entry from the protocols
database (see protocols(5)) and returns a protoent structure containing
the broken-out fields from the entry. A connection is opened to the
database if necessary.
The getprotobyname() function returns a protoent structure for the
entry from the database that matches the protocol name name. A
connection is opened to the database if necessary.
The getprotobynumber() function returns a protoent structure for the
entry from the database that matches the protocol number number. A
connection is opened to the database if necessary.
The setprotoent() function opens a connection to the database, and sets
the next entry to the first entry. If stayopen is nonzero, then the
connection to the database will not be closed between calls to one of
the getproto*() functions.
The endprotoent() function closes the connection to the database.
The protoent structure is defined in <netdb.h> as follows:
struct protoent {
char *p_name; /* official protocol name */
char **p_aliases; /* alias list */
int p_proto; /* protocol number */
}
The members of the protoent structure are:
p_name The official name of the protocol.
p_aliases
A NULL-terminated list of alternative names for the protocol.
p_proto
The protocol number.

RETURNVALUE

The getprotoent(), getprotobyname() and getprotobynumber() functions
return a pointer to a statically allocated protoent structure, or a
NULL pointer if an error occurs or the end of the file is reached.